Journal of Environmental Research

Effect of organic amendments on phosphorus sorption isotherm in some calcareous fertilized soils

Joint Event on 4^th International Conference on Pollution Control & Sustainable Environment & 6^th Edition of International Conference on Water Pollution & Sewage Management
July 26-27, 2018 Rome, Italy

Mahboubeh Zarrabi and Fatemeh Bagvand

University of Malayer, Iran

Posters & Accepted Abstracts: J Environ Res

Abstract

In order to enhance crop production in arid and semi-arid regions, high amount of phosphorous (P) fertilizer and organic amendments (OAs) together are added to soils. Addition of OAs to P fertilized soil may alter P sorption and availability in soil. The high P concentration in soil solution can increase movement of P from soils to surface water increasing eutrophication of water. In order to study the effect of OAs with different ranges of total P and C/P ratios, Phosphorus sorption isotherm was investigated in five P fertilized calcareous soils treated with four types of OAs (vermicompost, grape waste, poultry and sheep manure) at rate of 20 g kg-1 for one month. Isotherm experiment in control (not treated) and treated soils were carried out by concentrations of P range from 0 to 200 mg l-1 in the presence of 10 mm CaCl2. Sorption isotherms were characterized using Freundlich, linear and Langmuir equations. The grape waste had the highest (350) and vermicompost the lowest (15) C:P ratio. Average concentration of available P in control and treated soil with vermicompost, grape waste, poultry and sheep manure was 25.9, 628.4, 495.0, 553.3 and 577.1 mg kg-1, respectively. Phosphorus sorption curves were well fitted to the Freundlich equation. Kf and an average values were in the following order: control > grape waste > poultry manure > vermicompost > sheep manure. The SPR (standard P requirement) average of control and treated soil with vermicompost, grape waste, poultry and sheep manure was, 121.3, 11.0, 14.5, 12.8 and 9.3 mg kg-1, respectively. There was positive correlation between SPR with CEC and ECC percent of treated soils. Our study indicated that OAs with low C:P ratio and high total P had an important role in the sorption of P in calcareous soils.